Recently, as portable wireless terminals have been increasingly popularized, users need additional functions to their taste in opening and closing operation of a terminal, in addition to its inherent function of wireless communication.
In response to these needs, portable terminals have been developed into a bar type, flip type, flip-up type, folder type, and the like. Recently, the folder type has been used most widely.
This is because the folder type terminal has a space enough to adopt an LCD module as the display device and can be held in a folded state to thereby provide a good portability, as compared with other type terminals.
On the other hand, a slider type terminal has been introduced, which can be equipped with an LCD module display device having a similar size to the folder type. Simultaneously, the slider type can contribute to miniaturization of portable terminals.
This slider type terminal is structured such that a sub-body corresponding to a cover is slidably opened and closed on a main body, thereby providing additional advantages of slidably opening and closing, while maintaining advantages of the existing folder type terminal.
For example, Korean Utility Model Application No. 2003-0000136 discloses a slider-type portable wireless terminal.
The terminal disclosed in the above application a guide means for guiding a sub-body on a main body and at least one resilient means installed between the sub-body and the main body such that its resilient force can be exerted in opening or closing direction with respect to a certain sliding point of the sub-body. In addition, when the sub-body is completely opened and closed, it can remain in its opened or closed state due to the resilient means, without any separate stopper. The resilient means employs a torsion spring, one end of which is fixed to the main body and the other end thereof is fixed to the sub-body.
In this terminal, one end of the torsion spring is fixed to the main body and the other end thereof is fixed to the sub-body, and thus the resiliency of the torsion spring is exerted over the whole moving distance of the sub-body. Thus, the torsion spring is compressed and stretched over a wide length. Therefore, the torsion spring employs one expandable over a wide length, but having a smaller resilient force. In order to compensate for the deficient resilient force, two torsion springs are employed.
Accordingly, in the above-described conventional opening and closing apparatus, the torsion is deformed in a wide range and easily degraded due to fatigue caused by repeated operations. Thus, the torsion spring comes to lose its normal function within a shorter period of time.
In addition, as a guide means for guiding the sub-body on the main body, the above conventional opening and closing apparatus is provided with a guide slit formed lengthwise in both lateral sides of the main plate. The slider plate includes a guide rib to be slidably coupled to the guide slit.
In the above terminal, the guide rib slides along the guide slit, and thus the slider plate and the sub-body is configured to be opened from the main plate and the main body.
In the conventional opening and closing apparatus, however, the guide slit is formed in the main plate and the guide rib is formed in the slider plate. Thus, it leads to an increase in the thickness of the opening and closing apparatus, thereby providing a difficulty in making a slim terminal.
Furthermore, with the above conventional apparatus, a difficulty occurs in assembling the guide rib and the guide slit, due to clearance in component specifications. The repeated sliding motion of the slider plate on the main plate generates vibration, which may causes damage on components housed in a terminal. The sliding portion is abraded or clearance in assembled components occurs, thereby causing problems in smooth sliding of the slider plate.